The following are fuzzing vectors which can be used with WebScarab, JBroFuzz, WSFuzzer, or another fuzzer.
Fuzzing is the "kitchen sink" approach to testing the response of an application to parameter manipulation. Generally one looks for error conditions that are generated in an application as a result of fuzzing.
This is the simple part of the discovery phase.
Once an error has been discovered identifying and exploiting a potential vulnerability is where skill is required.

Recursive fuzzing

Recursive fuzzing can be defined as the process of fuzzing a part of a request by iterating through all the possible combinations of a set alphabet. Consider the case of:

http://www.example.com/8302fa3b

Selecting "8302fa3b" as a part of the request to be fuzzed against the set hexadecimal alphabet i.e. {0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f} falls under the category of recursive fuzzing. This would generate a total of 16^8 requests of the form: